Compression Post Shim
After a couple of phone calls to Catalina, I received a 1/2" shim to place under the compression post in our Cat 310 #12. The post is 1/2" too short and when we tightened the backstay, the downward force was shared by the bulkhead aft of the V-berth.
I made up a blocking arrangement which included a 12 ton bottle jack and over a several hour period I gently increased upward pressure just forward of the compression post. When I had the 1/2" gap under the lower plate I slipped in the shim, lined up the screw holes and gradually let off the pressure. I shot a little 3M 5200 in the screw holes and installed new screws (1/2" longer than the original).
Sorry to say, I did not take pictures. I did not want my wife to see a 12 ton jack in the V-berth so no pics and she was not allowed on board until all was finished.
I can give more detailed instructions and sketch a diagram for those that are interested.